title: Influence of work shift on glutamic acid and gamma-aminobutyric acid (GABA): evaluation with proton magnetic resonance spectroscopy at 3T.
abstract: Working conditions such as shift work constitute a well-known risk factor for insomnia and excessive daytime sleepiness complaints. We compared brain gamma-aminobutyric acid (GABA), glutamic acid (Glu), glutamine (Gln), and Glx (Glu+Gln) levels in day-shift versus alternate-shift workers with proton magnetic resonance spectroscopy ((1)H-MRS) at 3T. The study population consisted of 32 healthy adult volunteers (16 day-shift and 16 alternate-shift workers). Each subject underwent MRS conducted using a MEGA-PRESS sequence in the early morning and early evening on the same day. Spectroscopy voxels (3.0 cm × 3.0 cm × 3.0 cm) were placed in the frontal lobe and parieto-occipital lobe. The GABA/Cr ratio in the frontal lobe was significantly lower for the alternate-shift group than for the day-shift group in the early evening (1.885 vs. 0.875). For the other metabolite ratios (Gln/Cr and Glx/Cr), there were no significant differences between the two groups regardless of morning or evening schedule. Our preliminary finding represents a possible alteration of GABA content in the brain related to an irregular work schedule.
authors.affiliation: Department of Radiology, University of Occupational and Environmental Health School of Medicine, Kitakyushu 807-8555, Japan. kakeda@med.uoeh-u.ac.jp
authors.forename: Shingo
authors.initials: S
authors.lastname: Kakeda
authors.forename: Yukunori
authors.initials: Y
authors.lastname: Korogi
authors.forename: Junji
authors.initials: J
authors.lastname: Moriya
authors.forename: Norihiro
authors.initials: N
authors.lastname: Ohnari
authors.forename: Toru
authors.initials: T
authors.lastname: Sato
authors.forename: Susumu
authors.initials: S
authors.lastname: Ueno
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yanagihara
authors.forename: Masafumi
authors.initials: M
authors.lastname: Harada
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Matsuda
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D011522:Protons; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D011522:Protons; D001224:Aspartic Acid; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; C000179:N-acetylaspartate